A Sea Monster's Tale: In Search of the Basking Shark

By Colin Speedie

There are few marine creatures as spectacular as the Basking Shark. At up to 11 metres in length and seven tonnes in weight, this colossal, plankton-feeding fish is one of the largest in the world, second only to the whale shark. Historically, Basking Sharks were a familiar sight in the northern hemisphere – off the coasts of Norway, Scotland, Ireland, Canada and the USA, for example. In an 18th Century world without electricity, they became the focus of active hunting for their huge livers containing large amounts of valuable oil, primarily used in lamps.

Catch numbers were small enough to leave populations largely intact, but during the 20th Century a new breed of hunter joined the fray, some driven as much by a need for adventure as for financial gain. With improved equipment and experience, they exploited the shark on an industrial scale that drastically reduced numbers, leading to localised near-extinction in some areas.

From the 1970’s onward a new generation took to the seas, this time with conservation in mind to identify where the shark might still be found in the waters around the British Isles, employing new technologies to solve long-standing mysteries about the behaviour of this elusive creature. Using the best of both old and new research techniques, the case was built to justify the species becoming one of the most protected sharks in the oceans.

Today, the Basking Shark is a much-loved cornerstone of our natural heritage. There are positive signs that the population has stabilised and may even be slowly recovering from the damage of the past, proving that timely conservation measures can be effective. Join us on a journey amidst wild seas, places, people and conservation history in the battle to protect this iconic creature – a true sea monster’s tale.

• Language: English
• Publisher: Princeton University Press
• Release date: Jun 8, 2021
• ISBN: 9780691232454

Book preview

Introduction

In a still sea on a calm Hebridean morning a giant shark is following our research yacht. Scarcely making any forward progress, this nine-metre-long monster has taken up station off our stern, and is slowly wagging its head from side to side, as if sniffing for some scent that might identify the yacht as friend or foe. Beside me, one of our volunteer crew is jabbering like a game show host, almost overwhelmed by the experience of his first encounter with Cetorhinus maximus, the mighty Basking Shark.

As well he might be. It’s not every day that you find yourself being approached intimately by such a behemoth. Capable of reaching up to 11m in length, this fish is longer than a London bus, but on first acquaintance it is not just the length but the colossal girth that astonishes. With its slow, sinuous movements, the Basking Shark is reminiscent of some creature from a long-forgotten age, and indeed it can trace its lineage back for many millions of years. Out here in this wild, intoxicating mix of land, sea and sky, it seems so perfectly at home, an essential ingredient of this timeless place, that we’re almost unsurprised to encounter it.

Yet in some ways it’s remarkable that we are able to experience this moment at all, as man has conducted a war of attrition on this harmless, plankton feeding fish for centuries, not least here in the Sea of the Hebrides off the West coast of Scotland.

Meet the beast

The Basking Shark belongs in the class of the Chondrichthyans, the cartilaginous fishes, in the sub-class Elasmobranchii, the sharks. The first shark is believed to have existed nearly 400 million years ago. Since then, sharks have diversified to inhabit a highly diverse range of habitats and a wide variety of lifestyles. Some evolved to become filter feeders and achieve great size, such as the Basking Shark, the Megamouth Shark (Megachasma pelagios) and the Whale Shark (Rhincodon typus). Of these three, only the Basking Shark feeds solely on plankton, and belongs in its own family, Cetorhinidae, of which it is the only living species. Fossil records suggest that sharks of the genus Cetorhinus that closely resemble today’s animal have existed since the middle Eocene, making the family at least 38 million years old.

Out on the water, the Basking Shark is a creature of such massive scale and obvious power that at first glance it can be hard to believe it is a harmless filter feeder. That first impression is heightened by the way that it closely resembles some of its relatives. The Basking Shark belongs in the order Lamniformes, along with many of the predatory oceanic mackerel sharks such as the White Shark (Carcharodon carcharias), the Shortfin Mako (Isurus oxyrinchus) and the Porbeagle (Lamna nasus), and shares many external features with them, including horizontal keels in the area of the caudal peduncle and a second anal fin. No doubt it is this resemblance that is one of the main reasons for the annual ‘silly season’ sightings of White Sharks that form a perennial staple amongst some of the more colourful British newspapers.

The Basking Shark is widely distributed around the world, mainly in warm temperate and boreal waters in the North Atlantic and North Pacific oceans, in the Mediterranean and in the southern hemisphere between South America, South Africa, Australia and New Zealand. Basking Sharks are generally sighted at the surface during spring and summer in the North Atlantic, along the continental shelf edge and coastal waters. Efficient foragers, they travel constantly to identify and exploit the best patches of plankton, and satellite tagging studies have shown that the species will migrate over thousands of kilometres and dive to depths in excess of 1,000m to seek out their prey.

Appearance

The massive body is cylindrical with huge pectoral fins and a large crescent-shaped caudal (tail) fin. There are two dorsal fins, the first being the huge ‘sail’ that is the first visible sign that gives away the presence of a Basking Shark at the surface, which can reach over one metre tall in the biggest fish.

The head is the most obvious and impressive element in adult fish, especially when they are feeding. When swimming with the mouth partly open, the head is slender with a conical, pointed rostrum (snout), and the eyes well forward. Once the animal opens its mouth to feed, the appearance of the head is completely altered, not only as the gape is around one metre (three feet) in a seven-metre shark, but also because the whole of the branchial region enlarges, looking rather like an approaching jet engine when viewed from ahead.

Five pairs of gill arches almost completely encircle the body, and fan open as the shark swims forward, allowing the water entering the mouth to pass through the filamentous gill rakers in the arches, filtering out the shark’s favoured planktonic prey, calanoid copepods, and allowing respiration. The inside of the mouth is bright white, with occasional small, darker blotches, a form of coloration that some researchers believe may attract the copepods. The jaws are rimmed by a pink strip of tissue with rows of minute, hooked teeth: six rows on the upper jaw and nine on the lower.

The Basking Shark possesses hundreds of tiny, hooked teeth, despite the fact that it only feeds on plankton.

Size

With a maximum total length in excess of ten metres (33 feet) the Basking Shark is the second largest fish in the world, exceeded only by another filter feeder, the Whale Shark of tropical seas, that can achieve lengths of up to 21 metres. It has been suggested that the maximum weight of a nine-metre (30ft) individual would be 6.5–7 tonnes, whilst a more recent study using an isometric length–weight relationship proposes a maximum weight for a 10m individual of 7.5 tonnes.

The Whale Shark can reach up to 21 metres in length, more that twice the length of a Basking Shark at over 10 metres.

Basking Sharks have often been described by researchers as being ‘dark-grey, almost black’, but this is probably due to the small number of sharks examined and the fact that they were dead animals that had been allowed to become dry. After death the colour and markings can fade and change, giving an erroneous impression of the true colour. In living animals, colour varies considerably, and the shark has attractive python-like markings that run from the top of the head down the length of the body.

The skin is deeply fissured and is covered in minute sharp denticles that are highly abrasive to the touch. The skin is coated in a dark, acrid-smelling slime that may have anti-fouling properties, to ward off parasitic copepods such as Dinematura producta and the Sea Lamprey (Petromyzon marinus) that attach themselves to the skin of the shark. Many sharks seem to carry these creatures, particularly in the ventral area around the cloaca, although the scars left by their attachment can often be seen even on the fins.

Life history and reproduction

Basking Sharks are believed to be long-lived, perhaps reaching 50 years of age. The females are believed to reach sexual maturity at around 18 years, with males reaching that life stage slightly younger, at around 17 years. Mature males are equipped with two external sexual organs called claspers, that are around one metre long, and form a claw to stay in place during copulation. The gestation period is believed to be one of the longest of all species, at up to 2.6 years, when five to six live pups of 1.5–1.7m in length are born. There may be a two to four-year gap between pregnancies. Due to a lack of natural predators, the rate of natural mortality may be as low as 0.091. If these figures are correct, the species may have among the lowest natural mortality and productivity levels calculated for a commercially fished marine species.

Senses

Basking Sharks are equipped with the same sensory faculties as other sharks, notably a powerful sense of smell that may help them locate dense patches of zooplankton, as well as electroreception via the ampullae of Lorenzini, pit organs concentrated on the snout that are sensitive to electrical fields. As dense aggregations of zooplankton will almost certainly produce detectable electrical activity, this may be a further cue that the shark can employ to forage actively for the best patches of plankton. Eyesight is not especially developed, but is acute enough to identify potential threats such as small craft or swimmers at close range.

Basking at the surface

Surface swimming is really the tip of the iceberg. At any one time that a shark is sighted at the surface, there are many, many more out of sight in the depths. Surface swimming is another form of foraging behaviour, when dense patches of zooplankton are high in the water column, and the sharks track those patches to exploit them. The Basking Shark, like other sharks, possesses no swim bladder to provide buoyancy, but instead has a massive bi-lobal liver filled with oil. This acts as an energy reserve when plankton is less dense or when the shark is migrating, and as a hydrostatic organ, a ‘hepatic float’ capable of maintaining the shark at almost neutral buoyancy. The liver oil comprises almost 40% squalene, a terpenoid hydrocarbon that has a low specific gravity, and it is this compound that is mainly responsible for buoyancy. And it was this oil that was the main driver for the large-scale pursuit of the Basking Shark.

Basking Shark distribution in the North-east Atlantic, including key historic hunting sites.

Around the world, from Norway to the United States and from Ireland to Canada, many tens of thousands of these creatures were killed for that valuable liver oil, to light city streets and remote coastal dwellings. In the early years the hunt was on a relatively small scale, with Basking Sharks taken only on an opportunistic basis. But as demand increased to light city streets, so the hunt was intensified and became a significant threat to the species before the arrival of paraffin on the market offered a cheaper alternative.

At times considered a pest that damaged fishing nets and gear, fisheries protection vessels were sometimes employed to slaughter Basking Sharks in significant numbers. In the aftermath of World War II, a global shortage of high-grade oils meant that prices for the liver oil rocketed, prompting commercial fisheries for the species to become established and expand rapidly. Latterly, demand from the insatiable shark fin trade in Asia put a further bounty on the heads of Basking Sharks. These fisheries were on a hitherto unprecedented scale and were highly mechanised compared with previous exploitation efforts. As a result of these changes, the take of sharks increased exponentially, and it is likely that over 100,000 Basking Sharks were killed in the North-east Atlantic alone in the last 55 years of the twentieth century.

These pressures, over at least two centuries, combined to bring the Basking Shark to the brink of localised extinction in several places. Even today, at many sites where the Basking Shark was once considered seasonally abundant, sightings of animals remain drastically reduced. Perhaps now, with the collapse of those fisheries and the development of conservation measures to protect the Basking Shark, it may be hoped that populations can make a recovery and return to grace their old haunts once more.

But how to know whether such a recovery is underway, when the creature you wish to study spends more than 99% of its life out of sight, below the surface of the water? For decades the scientific record held little more than informed speculation about the ecology of the Basking Shark, combined with a broad understanding of the biology of the species gleaned from stranded or harpooned specimens.

Fortunately for the shark, at the same time that the nascent conservation movement identified the Basking Shark as a key species in need of protection, science was making giant steps in its ability to track animals wherever they might travel, and through the use of new technologies such as satellite tracking, many of the enduring mysteries concerning the shark and its whereabouts when below the surface have now been comprehensively laid to rest.

Hope for the future?

Over the last 70 years, attitudes towards the Basking Shark have swung dramatically from seeing the species as a valuable commercial prey or a ‘plague on fisheries’ to a ‘gentle giant’ in need of protection. For the hunters in Scotland after the cataclysm of World War II there must have seemed nothing ignoble about hunting the species to provide valuable liver oil in a time of necessity. To the fishermen in Canada who saw their nets destroyed by Basking Sharks, it must have seemed entirely reasonable to demand action to rid their waters of these ‘pests’. But that was then and this is now, and the drastic reduction in numbers of these extraordinary creatures as a result of those historic actions demands that we do all we can to safeguard the remaining populations from further harm.

In the aftermath of the decimation of the species through exploitation, some questions remain unanswered. Where have the sharks gone from many of their favourite haunts, and is that absence entirely the fault of man? Fortunately, a road map of sorts exists for some areas, notably in Scotland. Some of the local hunters there during the last era of hunting left highly readable accounts of their travails, allowing for insights to be made into the distribution and abundance of the Basking Shark, at least in some small areas of the sharks’ former range.

Which is what has brought us here at this moment, as part of a project to establish whether there are still shark ‘hotspots’ in British waters, post-hunting, where these creatures can be seen in abundance. Our aim is to try and identify any such sites – if they still exist – to record Basking Shark numbers and social behaviour, with a view to securing further protection for those sites. This slow, painstaking work, in the often-difficult weather that plagues the wild waters of Britain’s western seaboard, leaves us with a keen insight into the difficulties faced by the shark hunters, and a far greater respect for them as a result.

In time, our work will also teach us much about the local and global politics that dictate the terms on which creatures retain the chance to survive through protection – or not. It is, after all, one thing to build a case for a ‘charismatic megafauna’ beast like the Basking Shark, whilst many smaller, less obvious but no less important creatures never get noticed at all. But if you can’t achieve protection for an iconic creature like the Basking Shark, then what hope is there for any species?

None of that matters right now, though. We’re simply awestruck to find ourselves in this wonderful place with this extraordinary creature on our trail, and filled with excitement in anticipation of the journey of discovery ahead of us.

Chapter 1

The Early History

Given that whaling is believed to have started sometime in the eleventh century in northern Europe, it seems surprising that a huge fish that seasonally inhabited the same waters as whales might have gone unrecorded for so long. Yet it wasn’t until over 500 years later that the Basking Shark first makes an appearance in the world of science.

The Basking Shark was first described, illustrated and given a scientific name in 1765 by Johan Ernst Gunnerus, bishop of Trondheim, in an article published in Der Trondheimske Selskabs Skrifter (Transactions of the Trondheim Society). As a travelling bishop with a large diocese, Gunnerus was able to indulge his enthusiasm for the natural world as he visited his parishes, making many worthwhile contributions to the understanding of the flora and fauna of Norway.

Having heard of a hunt developing locally for the Basking Shark (which he called the ‘Brugde’) in Norway, he made it his business to learn more about the creature, and during one of his regular diocesan journeys to Nordland, a region north of Trondheim, he met a man involved in the nascent fishery. This landowner arranged for his foreman to send him an account of the fish, and in due time Gunnerus received a drawing, a piece of skin and a carved wooden model of the shark. Later, a stuffed skin nine metres long was sent to him from the island of Smolen, and upon this evidently well-preserved specimen he based his scientific description. Having examined the specimen, it was clear to him that this was not any previously described shark, but was in fact a new species to science.

The first recorded illustration of a Basking Shark, as described by Johan Ernst Gunnerus.

A stranded male Basking Shark on a beach entertains sightseers. Note that the male sexual organs (claspers) have been interpreted as legs and feet! From Harpers Weekly 24th October 1868.

A regular correspondent with the renowned Swedish systematist, Carl von Linne (Linnaeus), Gunnerus adopted Linnaeus’s binomial system to name this new shark Squalus maximus (the biggest shark). Linnaeus incorporated this name into the 12th edition of his Systema Naturae of 1776, establishing once and for all that Gunnerus was the first person to make a scientific description of the shark. The scientific name remained in place until 1816 when Henri-Marie de Blainville of the Paris Natural History Museum created a new sub-genus Cetorhinus for the Basking Shark, and the species remains Cetorhinus maximus (Gunnerus 1765) to this day.

Around the same time another correspondent with Linnaeus, the Welsh naturalist Thomas Pennant, made the first report of the Basking Shark in his British Zoology of 1769. Working from reports sent to him by two Anglesey rectors well acquainted with a local fishery for the creature, and from samples of skin, jaws and gill rakers, Pennant proposed that the creature was indeed a shark, as opposed to a whale, especially due to its vertical tail. Despite containing a number of unavoidable errors (he had not yet examined a full specimen), his treatise contained one contribution that has lasted to this day. He proposed to name his shark the Basking Shark, after its habit of ‘lying as if to sun itself on the surface of the water’.

He made this change from the name commonly used in Ireland and Wales, the sun-fish, largely to avoid confusion with the huge Ocean Sunfish (Mola mola) that was an irregular visitor to Britain’s shores. However, he retained the imagery of sun-fish, that of a creature that rises to the surface to ‘bask’ in the sunlight, when the truth is far more prosaic, in that the shark only spends time at the surface when its planktonic prey are there. But the name has stayed and it is a popular name that works well.

Pennant travelled to Scotland some years later on a fact-gathering expedition to produce an enlarged edition of his book, A Tour in Scotland. On this, his second voyage to the region, he expended his itinerary to take in the Hebrides, landing at Loch Ranza on Arran in the Firth of Clyde in late June 1772, just in time to make his first encounter with a Basking Shark. An 8.3m shark had been captured and was lying on a nearby beach, giving him a perfect opportunity to inspect the carcass. The information he gleaned from the fishermen and the data that he gathered from the stranded shark greatly added to the text of A Tour in Scotland and Voyage to the Hebrides 1772 and included a fine drawing of the hunt he had witnessed.

His later edition of British Zoology included an enhanced description of the Basking Shark derived from the animal he inspected at Loch Ranza. It also included one of the earliest sketches of a Basking Shark which, although far from exact, is certainly no more bizarre than many of the others that came later, all of which likely suffered from being depictions of dead animals that had collapse of tissue or other early forms of decomposition. It is worth considering just how different a Basking Shark looks alive in its natural habitat, than decomposing on a beach. Such a soft, cartilaginous creature adopts some really strange contours when removed from its buoyant environment. Coloration and body markings change or fade, and in no time at all, a stranded Basking Shark looks very altered from the living creature.

There is no actual record of who drew the shark, but Denis Fairfax, in his excellent book The Basking Shark in Scotland, suggests two plausible alternatives. The first is the more obvious, that Pennant instructed the artist who accompanied him on his second tour of Scotland, Moses Griffith, to draw the shark he examined at Loch Ranza. As Moses Griffith drew the harpoon hunting scene in the same book in which the shark depiction is published, this seems a reasonable hypothesis. But Fairfax also suggests an intriguing alternative, that one of Pennant’s ecclesiastical correspondents, the Reverend George Low of Birsay in Orkney, also sent him a sketch of a Basking Shark that had been harpooned close to his home. Once again the sketch would have been from a dead specimen, with all of the usual difficulties inherent.

The same problem affected many of the speculative (and some downright wild) identifications that were to be subsequently derived, especially those that came from well-intentioned but amateur naturalists around Britain. Foremost amongst these was Dr Jonathan Couch, a physician from the tiny fishing port of Polperro on the south coast of Cornwall. Seldom travelling from his home town, Couch devoted his life to the well-being of his fishermen patients. In return he was able to indulge his fascination with fish, examining and drawing a wide variety of specimens that his patients brought to him, some of which were later published in scientific journals. He eventually produced a four-volume series entitled A History of the Fishes of the British Islands, that included not only the Basking Shark but also two ‘new’ species, based on drawings that had been sent to him by correspondents. He named these two creatures the Rashleigh Shark (Polyprosopus rashleighanus) and the Broad-headed Gazer (Polyprosopus macer). To be fair, the drawings suffered from the usual problems of drying out, shrinkage and decomposition of the head area, and the wonderfully weird looking Broad-headed Gazer, with its very pointed snout, looks to have been drawn from a very young animal where the rostral area is more elongated than in an adult. But there’s no doubt that they are both Basking Sharks, even though the drawings do their best to convince you otherwise.

Early attempts to capture the living animal in its natural habitat were seldom very accurate, having been drawn from second-hand reports or stranded animals. From Couch, A History of the Fishes of the British Islands 1860–65.

Undoubtedly it is the way that a dead Basking Shark appears in the more advanced stages of decomposition that has led to some of the more eccentric attributions to the species, in the form of sea monsters. The first thing to disintegrate is usually the gill arch and jaw area, leaving the small skull attached to the long spinal column, resulting in an almost dinosaur-like appearance. The more solid cartilaginous attachments of the pectoral and anal fins, and the claspers (if a male) are much slower to break down, and the remnants of their attachments were sometimes attributed to being part of three apparent pairs of legs. The tail is another early departure, leaving a long, slender spine, and the whole resembles nothing more than a plesiosaur, albeit with legs instead of fins. So on many occasions when a badly decomposed Basking Shark comes ashore or is trawled up from the seabed, sensation, dispute and disappointment have soon appeared on the scene.

Perhaps the best documented of these creatures comes from Britain: the so-called Stronsay Monster. Denis Fairfax describes how in 1808 some fishermen found the decomposing carcass of what they thought to be a whale floating off the island of Stronsay in the Orkney Islands. When it washed ashore later the news soon spread, and it wasn’t long before speculation as to its origin began. At a meeting of the learned Wernerian Natural History Society in Edinburgh, members heard that the remains most resembled the ‘Great Sea Snake of the Northern Ocean’ as described by Hans Egede, Bishop of Greenland in 1734 and Erik Pontoppidan, Bishop of Bergen in 1755.

The scene having been set, nature lent a helping hand when a storm all but wiped out the remains, leaving only the skull, a few attached vertebrae, a fin and some gill cartilage. Fairfax reports that these remnants were sent to Edward Home, a celebrated surgeon and anatomist, and a regular contributor to scientific journals. Home gathered the affidavits taken from the men who had seen the creature, together with a drawing made some six weeks afterwards. Home didn’t take long to come to his judgment; these were the remains of a Basking Shark. And whilst he didn’t doubt the sincerity of the men who had provided the information that led to the drawing, he was very much of the opinion that the men had read that the creature might be Pontoppidan’s maned sea serpent, which had clouded their judgment.

Not everybody shared his view. In January 1809 Dr John Barclay, anatomist and founder member of the Wernerian Society, made a presentation to the members of that Society on the ‘Great Sea Snake’. At the same meeting one Patrick O’Neill proposed that the animal be from a new genus Halsydrus, with the proposed addition of pontoppidani to underpin his belief that the creature was the one described by Pontoppidan. A monster was born.

However, Home was a very learned man, and had an existing interest in the Basking Shark. As a surgeon and anatomist, his main interest lay in anatomy and physiology, not in sea monsters, and having made a careful examination of the remaining physical parts of the creature, he was well placed to pronounce on the matter. When he presented his finding to the Royal Society in London in May 1809, it might be easy to imagine that his word alone would have carried the day. But not a bit of it, and Barclay hit back with rebuttals of Home’s arguments in 1810 and 1811. The dispute grumbled along for more than 40 years, with Orcadian naturalist T.S. Traill still insisting that the Stronsay monster was no known shark. There are probably people who would agree with him today, for there are still periodic ‘discoveries’ of sea monsters, that have all eventually been proven to be Basking Sharks, ranging from British Columbia (several), Orkney again (Scapasaurus) New Zealand, and most recently the Philippines.

Dr Jonathan Couch identified two ‘new’ species that were undoubtedly both Basking Sharks. Above: the Rashleigh Shark (Polyprospus rashleaighanus). Below: the Broad-headed Gazer (Polyprosopus macer). From Couch, A History of the Fishes of the British Islands 1860–65.

Another possible way in which the Basking Shark has entered the world of cryptozoology is via its behaviour observed at the sea surface. Groups of sharks feeding at the surface, and especially those engaged in what is believed to be courtship behaviour, often swim in long lines, closely following each other with noses, dorsal fins and caudal fins showing. When seen from a distance they look like nothing other than a sea snake or plesiosaur.

A famous example of this may be Cadborosaurus willsi (‘Caddy’), named from an original sighting in Cadboro Bay, Victoria, British Columbia. Between 1881 and 1991 there were 181 reports of ‘Caddy’ from around that area, at least some of which proved to be Basking Sharks. A book on the mythical creature, Cadborosaurus: Survivor from the Deep, pointed out that there was a significant rise in the number of ‘Caddy’ sightings between 1930 and 1960, which Scott Wallace and Brian Gisborne identify in their fascinating book, The Basking Shark, the slaughter of BC’s gentle giants, as a period coincidental with Basking Sharks being abundant in those waters.

Even closer to my home these reports still occur. Many years ago, on a beautiful calm evening, I stood watching Basking Sharks from the extremity of Black Head, a promontory on the eastern side of the Lizard peninsula in Cornwall. I was just about to pack up and go home, when I was joined by an elderly but very hale and hearty lady who asked me if I was watching ‘Morgawr’. I replied no, I was watching Basking Sharks, and pointed out a small group well offshore. Emphatically, she said, ‘No, that’s Morgawr, Cornwall’s sea serpent. I watch him all of the time’. To this day I have no idea if she was pulling my leg, but her scornful tone did suggest that I was obviously simple and should have known better.

Chapter 2

The First Hunters

The first descriptions of the Basking Shark came about as a by-product of commercial fisheries in 1765 (Gunnerus, from Norway) and 1769 (Pennant, from Wales). The close relationship between those dates suggests that the hunting of the Basking Shark began almost simultaneously across a wide range. It soon gathered momentum, developing into a sustained fishery that would be actively prosecuted over a wide front in the North-east Atlantic, from Ireland through Scotland, Iceland and Norway.

Fish, whale and seal oil were already established commodities in those places, mainly for local use. It would have been logical for the inhabitants of those coasts to take advantage of any other sizeable animals (including Basking Sharks) that came ashore, and they would surely have soon recognised the value of the sharks’ livers to furnish oil. Basking Sharks do strand or are washed ashore from time to time, often as the result of accidental capture in fisheries for other species, and local people would undoubtedly have eyed such substantial prizes for their potential benefits such as the skin, which was occasionally used as a crude form of sandpaper, as well as their liver oil. Denis Fairfax cites historical reports from Iceland that describe liver oil being extracted from stranded Basking Sharks, and there is no reason to assume that fishermen in Ireland or Scotland would have been any less ready to take advantage of such an opportunity.

Drive fisheries, where boats trapped small whales in bays and then chased them ashore, were also widely practised all around the Highlands and Islands of Scotland (and still are in the Faeroe Islands) and there is some evidence that similar tactics were employed for the Basking Shark, at least in parts of Loch Fyne, Scotland:

The sun or sail-fish occasionally visits us; this sluggish fish sometimes swims into the salmon nets, and suffers itself to be drawn towards the shore, without any resistance, till it gets near the land, that for want of a sufficient body of water, it cannot exert its strength, in disentangling itself from the net, the fishers in the meantime take advantage of its situation, and attack it with sticks and stones, till they have it secure.

Fairfax quotes another report from the Orkney Islands telling of local people catching a shark by ‘throwing a noose of rope over his pectoral fins, and playing him’, so it seems likely that opportunistic hunting of the Basking Shark to supply local needs may have taken place over a wide area for some considerable time before the development of a truly commercial hunt.

The first actual record of the process of hunting the Basking Shark comes from Ireland in 1739, when William Henry described a hunt in Donegal Bay:

The fishermen, making up to them, strike them with their harpoon irons. Whereupon they dart to the bottom and rolling on the ground, work the harpoon into the wound. Then being irritated, they rise again to the surface and shoot away with an incredible velocity dragging the boat after them, and they bear way sometimes for leagues; till at last dying, they float on the surface till the fishermen come along their side, and cut out the liver, which affords several barrels of oyl. In this dangerous war with these smaller leviathans, it is necessary to have 100 fathoms of small cord fixt to the end of the harpoon, to give it play: and for a man to stand by the gunnel of the boat, with a hatchet, to cut the rope in case of any stop in its running off, or the fish’s emerging too suddenly; either of which accidents might overset the boat.

This vivid account indicates that it was already a well-organised fishery.

In 1740 an invitation to tender to supply sun-fish oil appeared in the Dublin News Letter. As the tender also requested supplies of rapeseed oil, Kenneth McNally in his fascinating book, The Sun-fish Hunt, suggests that it seems likely that both requirements were intended for street-lighting purposes. This argument is further supported by a reference he quotes from 1742 concerning street lighting in Galway and Waterford that specified ‘sufficient lights to be lighted up and continue burning with double wick and a sufficient quantity of rape oil of the produce of this Kingdom, or of sun-fish oil made in this Kingdom’, which suggests that a local sun-fish hunt was already an established feature of Irish coastal life, at least on the west coast.

It appears that the fishery might have been generated by a combination of increased abundance in correlation with the development and expansion of whaling. In 1744 it was reported that ‘the coasts of Ireland, especially those in the west, have of late years been much frequented by whales and sun-fish, which come in March or April and stay till November’. In the years just prior to that report there had been a popular campaign to encourage the establishment of whaling activity on the north-west coast of Ireland, encapsulated in the short poem that opens McNally’s book:

Equip your boats with sharp Harpoon and Lance,

Let’s strive our publick Treasure to Advance;

So shall returning Gold reward our toil,

When London Lamps shall glow with Irish Oil.

Indeed, a Lieutenant Chaplain had taken up the challenge in 1737, and had established a short-lived whaling venture based around Killybegs on the northern shore of Donegal Bay. Unsuccessful though it may have been, it would have at least offered some training to local men in the art of harpoon fisheries, and the rendering down of body material to obtain oil, which may well have proved useful in the prosecution of a parallel Basking Shark fishery.

Donegal Bay, Ireland.

In 1750, Charles Smith described the fishery: ‘the liver affords from twenty to one hundred gallons of oil. They are struck with harpoons and are well worth looking after’. It seems that by this time there were established uses and potential markets for considerable amounts of oil to be used in a variety of ways. The oil could be burned in the small ‘cruisie’ lamps that were the main source of illumination in the cottages of the coast, with the advantage that it was less smoky than other traditional fish oils, such as those obtained from herring or dogfish. Other uses included preserving timber and dressing wool, while the oil was often used as a salve or balm for injuries and aching limbs. But the most attractive prize must have been the development of a lucrative market for the high-grade oil for municipal lighting.

As Martin McGonigle reports in a paper on the establishment of a whaling and shark fishing station in Donegal Bay, it seems likely that this valuable commercial opportunity was the driving force for Andrew and Thomas Nesbitt when they established a large-scale whaling and shark-hunting station at Inver Port, near Killybegs, around 1760. In 1759 Thomas Nesbitt was already well established in both the herring fishery and hunting Basking Sharks. It seems logical to assume that the investment in plant and manpower was largely driven by his success in taking Basking Sharks, and the experience he had gained in harpoon fisheries and rendering down their livers for oil. In order to expand his operation, Nesbitt travelled to London to buy a whaling ship of 149 tons, which carried five whaleboats as catchers, and hired experienced men who had spent time whaling in Greenland. This substantial extra capacity in terms of men, gear and vessels to pursue whales also had significance for the hunting of sharks. As one reporter observed, ‘the sun-fish are seldom caught, except by boats belonging to the whale fishery’. This was reflected in the capture of 42 Basking Sharks by the Nesbitt fleet in one week in 1761, an astonishing figure for that era, where other Basking Shark fisheries appear to have been limited to low-impact artisanal enterprises.

Such a professional attitude to the hunt was almost certainly the exception rather than the rule. Most of the men involved were farmers and fishermen, who, like their Hebridean counterparts, supplemented their income by seasonally taking part in the Basking Shark fishery. McNally reported that at the end of the eighteenth century Galway alone had between 40 and 50 boats involved. Small, open sailing vessels known as Galway hookers, the tough and seaworthy gaff-rigged craft that were the workhorses of the west coast and islands, were the preferred vessels for these men. Some even used the lightweight open curraghs, seemingly flimsy but amazingly seaworthy hide-covered boats, an act (as far as I am concerned) that must have required either extraordinary bravery or absolute desperation. McNally quotes The Galway Weekly Advertiser of May 1823:

SUN FISHERY – We are happy to learn that the boats have been very successful in killing a number of sun-fish this season; the weather has been extremely favourable for the last three or four days; and we understand there are now upwards of one thousand boats upon the bank, seeking to take this most valuable fish, the consequence is, that no fresh fish of any kind is to be had in our market.

Even though there may be some doubt about the number of boats involved, it is evident that the fishery was viewed as being of such high importance to the local farmers/ fishermen that they dropped everything (including fishing for other commercial species) to take part. The driving force must have been profit, the value of the liver oil driving men to take such chances that ‘the poor fellows will risk even their lives to secure one of these fish’. The west coast of Ireland is a harsh and unforgiving place, which could support only subsistence agriculture, so the chance to secure such a valuable reward was apparently more than enough to draw those men away from tending to their farms, as was reported by the Commissioners of Fisheries: ‘The pursuit of sun-fish or Basking Shark in the months of April and May employs a good many hands at a season particularly inconvenient … a considerable capital is applied to navigation, though very little to agriculture.’

The bank referred to in the Galway report is almost certainly the Sunfish Bank, and it was well-known to the fishermen of the coast that abundant shoals of Basking Sharks were to be found there in season, much larger than the scattered groups encountered closer to shore. In 1825 The National Fishing Company proposed the establishment of a fishing station at Inishbofin, an island off the coast of Connemara, precisely because of its proximity to the bank. The station was planned to support larger, more seaworthy vessels that could stay at sea in more challenging conditions and so pursue the seasonal opportunity afforded by the presence of the shoals of sun-fish. Construction of the station didn’t go ahead, but the logic of using larger, more independent vessels to support small catcher craft was sound.

Although the west of Ireland did not have an abundance of larger vessels, they did have plenty of small craft and fishermen expert in handling them. Regional surveyor Hely Dutton reports that the small craft from Galway and Connemara took between 100 and 200 sharks there between 4 and 5 May 1815, which gives an indication of the size of the shoals. It is worth considering what a serious undertaking it would have been to fare 30 or 40 miles out to such an exposed site far from the rugged coastline of Achill Island. Almost out of sight of land on a clear day, in the ceaseless swell of the North Atlantic, exposed to rapidly changing weather and in a strong run of tide, this would not have been a place to linger except in the best of weather. As one local told the 1836 Commission of Enquiry:

Off the coast, about thirty miles or just within sight of the high land of Achill Island, is the ground called the Sunfish bank; we are on it with Sleavemore Achil, about E.N.E. per compass, seventy to ninety fathoms. The bank is remarkable for the break of the tide on it, with ebb and flood, and is supposed to be a ridge of land extending from the Blaskets to Erris Head, in about seventy fathoms. Half a mile further off we have fifteen fathoms more water, and the increase of depth is also considerable within it; the water outside deepens quickly to 100 fathoms and upwards; and the probability is, that the bank is nearer the edge of soundings.

And another confirmed:

There is a bank along the whole of the Galway coast, which extends from Inniskea, of the coast of Mayo, to the islands of Arran; about this bank, and still further to sea, are to be found the Basking Shark, or Sunfish.

‘Remarkable for the break of the tide on it’ and ‘still further to sea’; these are the sort of remarks that would have been immediately picked up on by any mariner listening to such accounts. Given the distances and the slow speeds attainable by the small craft of the day, it would come as no surprise that boats going out to the bank might be expected to remain at sea for days on end, and the men in them to go without food for 24 hours or more while they played the sharks. The rewards must indeed have been great, and the potential kudos immense for the men who pursued the sun-fish for it to have been worthwhile. As local lore of the time pointed out ‘A boatman was little esteemed long ago until he had spent a season or two at the Sunfish Bank’.

Given the dangers of hunting sharks at such a dangerous location, it should be noted with little surprise that when the fishery began to decline in the west of Ireland, crews stopped going out to the Sunfish bank. Instead, the hunters preferred to chase sharks that appeared in the bays and around the headlands along the coast. But as we shall see in a later chapter, that would not be the end of hunting the Basking Shark on the Sunfish Bank.

At around the same time, across the sea in the Highlands and Islands of the west coast of Scotland, the potential value of hunting the Basking Shark on a commercial basis hadn’t gone unnoticed. Thomas Pennant clearly knew of their distribution in the North-east Atlantic when in 1772 he reported:

They inhabit most parts of the western coasts of the northern seas: Linnaeus says within the arctic circle: they are found lower, on the coast of Norway, about Orkney Isles, the Hebrides; and on the coast of Ireland in the Bay of Balishannon and on the west coast about Anglesea

As we saw earlier, the Norwegian fishery was already established by the time that Gunnerus described the Basking Shark, to which we can now add both Donegal Bay and Anglesey as existing hunting grounds. Pennant was equally aware of an experimental commercial fishery from the previous decade, established on the island of Canna in the Inner Hebrides. As in Ireland, and indeed elsewhere, it must surely be the case that Canna was selected on the basis of an existing resource of Basking Sharks nearby.

This experimental fishery was the brainchild of Donald MacLeod, tacksman of the island, who obtained a grant of £250 (over £30,000 in 2017) from the Commissioners for the Annexed Estates to buy a vessel and tackle to hunt the ‘cairban’ (the local Gaelic name for the Basking Shark) as well as to fish for cod and Ling (Molva molva). His grant application made the somewhat grandiose claim that he was ‘the first that ever discovered the Cairban and proved successful in killing them; and that he has instructed several people on the west coast in the method of catching them’. If this is correct, then we can safely assume he had existing experience prior to 1766, his first season with his new vessel and equipment.

Early hunters and key hunting sites in Scotland.

Due to the late arrival of his grant, he started the 1766 season very late in the season, but still managed to take seven sharks between Rum and Canna. Finding the vessel ‘too expensive and unwieldy for the Kerban’ he sold the large vessel and bought two smaller ones. In the 1767 season he took eight Basking Sharks in the same area, a disappointing figure for a whole season’s effort. Seemingly depressed by the lack of success, not only in terms of shark hunting but also the cod and Ling fisheries, he reported to the Commissioners in 1768 that he was discontinuing his ‘tryalls’. However, despite his pessimism, a group of Directors of the British Fisheries Society who visited the island in 1787 found that ‘A great many Sun-fish or Basking Sharks are taken in these seas. The liver is oily, and the only part of the fish that is made use of ’. They also found that the local people were ‘a sober, quiet industrious race, and not contemptible fishers, especially of the sun-fish’. Perhaps Donald MacLeod was simply unlucky with his experimental fishery, and had a couple of bad seasons when few sharks were present?

Farther south in the Firth of Clyde, another dedicated fishery had developed at about the same time as the experimental fishery centred on Canna. The earliest mention of this fishery comes from Tarbert, Loch Fyne, in 1768 when Archibald Menzies, the Inspector-General of the Commissioners for the Annexed Estates, reported that ‘One Stewart at Bute … has been pretty successful for some years past in this fishery with the Harpoon.’ As confirmation of this report, Menzies personally witnessed a Basking Shark hunt in action near Tarbert where a nine-metre fish was finally brought in and yielded 192 gallons of liver oil. This report, combined with Pennant’s report of the successful hunt in Loch Ranza, Arran in 1772, suggests that the local fishery was far from in its infancy, and was in fact an established activity practised over a wide area.

Archibald Menzies must have been impressed with the potential for this fishery, as in 1777 the commissioners agreed to provide a grant of £200 (£25,000 in 2017) to David Campbell of Shawfield, Islay. Once again, as in Canna, this was to fund an experimental fishery ‘for herring, for cod, and for cairban, which come at different seasons’. No record exists concerning the success of this experiment, but given that the site was reasonably close to Basking Shark hotspots around Tiree and Colonsay, local abundance must once again have been the driver. However, if it had been a success, then undoubtedly there would have been associated reports to that effect. But equally, as at Canna, the (apparent) failure of these experiments could likely have been put down to the very exposed nature of both sites, open to the worst of the weather and the fierce local tides. As we shall later learn, these are wild places indeed, and not for the faint of heart. By comparison, the waters of the Firth of Clyde are very sheltered except from the south, and have much weaker tidal flows. This would have allowed for far easier conditions for small open boats and their crews to harpoon and capture the sharks.

But despite the challenges inherent in pursuing the Basking Shark in the exposed waters of the Sea of the Hebrides and the Minch, there is evidence that the courageous men of the islands were just as willing to face the risks as their counterparts in more sheltered waters. By the 1790s it would appear that the fishery had gained considerable traction, and both artisanal and